The invention relates to a maintenance car for an elevated train. Elevated trains, up to the present time, have no special maintenance cars. Street vehicles have been used for maintenance, where the maintenance platform can be raised on a telescopic column. Such maintenance cars, however, can only be utilized on streets and other locations accessible to cars, not above rivers, houses, railroads, or in impassable terrain. The known maintenance cars hinder traffic in the street during their operation. It is also impossible to tow broken-down cars on rails with cars running in the street.
It is the object of the present invention to design a maintenance car operating in all areas of an elevated train. This is done by having the maintenance car run on the rail (generally, a monorail) of the elevated train, and by providing it with a maintenance platform extendible beyond the base of the maintenance car. This type of maintenance car can go to any location without hindering street traffic, and at its destination the maintenance platform is brought into position for the necessary maintenance work. If maintenance is required on the rail, only lateral or side extension of the maintenance platform is necessary to permit such procedure. It is, however, also possible to rescue people from cars which cannot move due to certain damage. For this purpose, the maintenance car is provided with a platform extension extendible longitudinally which is brought into position next to the inoperable car. If inoperable cars cannot be put back into service on the spot, the maintenance car can tow them.
The maintenance platform may be arranged below the bottom or on the roof of the maintenance car cabin. If it is located under the bottom of a suspended type maintenance car which is suspended from the rail, construction is simplified, as the mobility of the platform is not limited by the undercarriage of the maintenance car. The platforms in suspended maintenance cars are, furthermore, better suited for service to be performed at the rail. The maintenance car may be equipped with one maintenance platform below the bottom, as well as one on the roof, whereby the latter may be of simple construction and extendible by hand.
A further detail of the invention provides each end of the maintenance car with a cross rail on which a cross carrier travels, which supports the maintenance floor. Tilt guards may be placed between cross rail and cross travel carrier which guard against tilting of the extended service floor against the maintenance car. Preferably, the travelling cross carrier accommodates a travelling cross carriage to which the service floor is attached. In this fashion, further extension of the service floor, laterally from the maintenance car, is achieved.
The cross carrier consists, preferably, of a box-like profile and the center of the profile is provided with a lower longitudinal slot for establishing a connection between cross carriage and service floor, whereby the longitudinal slot is bounded by stays pointing down and forming guide faces, while opposing flanges follow the lower end of such stays. The lower flanges contribute to the increase in bending strength of the cross carrier. The bottom of the box-like profile forms raceways next to the stays for rollers running on the rail and carrying the cross carrier. The inside of the box-like cross carrier bottom forms runways for the cross carriage. Thus practically all surfaces of the cross carrier are used as runways and guide faces for extending the service platform.
In another detail of the invention each cross rail comes with a displacement motor which drives a chain engaging at fixed points at the ends of the cross carrier via a drive gear, and each end of the cross carriage is provided with engaging points for additional chains which lead to a fixed point at the cross rail around guide wheels arranged at the ends of the cross carrier. Thus, when extending the cross carrier, the cross carriage travels simultaneously in the cross carrier. The displacement motors of front and rear cross carriers are independently controlled and the cross carriers and consequently the cross carriers can be extended to various lengths.
This is important when utilizing an additional platform extension extendible in longitudinal direction; details of such extension will be given later on. If the platform extension must be positioned next to a broken-down rail car in a curve of the rail, the cross carriages must be extended to different lengths to adapt the platform extension to the bend of the rail. In order to facilitate such differential extension of the cross carriers, the maintenance floor is provided with at least one length compensation slot through which penetrates the cross carriage with a floor suspension equipped with wheels for the maintenance floor. The length compensation slot runs in longitudinal direction of the maintenance floor, and is long enough to compensate for maximum extension direction of the maintenance floor versus the maintenance car.
A further detail of the invention provides the maintenance platform with a maintenance floor with a platform extension movable in the floor longitudinal beams. The floor longitudinal beams of the maintenance floor are connected via cross beams above and below the platform extension, so that the maintenance floor surrounds the platform extension like a box, and the floor longitudinal beams of the maintenance floor are safeguarded against tilting. At the floor longitudinal beams, support rolls revolve around horizontal roll axles, and guide rolls revolve around vertical roll axles, resting on horizontal runways and vertical guide faces of the platform extension. The runways consist of horizontal flanges and the guide faces of stays of two platform extension longitudinal beams.
A platform motor is attached to one of the floor longitudinal beams, whose drive gear engages with a chain which leads around guide wheels arranged at the ends of the floor longitudinal beam and from there to fixed points arranged at the opposite ends of the platform extension. In this arrangement, the chain crosses and permits extension of the platform extension from the floor longitudinal beams as far as made possible by the guide. Being that the maintenance car is longer than the regular rail car, sufficient guide length is guaranteed for the platform extension at the floor longitudinal beams.
A railing may be mounted on the maintenance platform. To this end the edge of the maintenance floor and platform extension is provided with tubular railing brackets into which railing posts are inserted. After extension of the maintenance floor and/or platform extension the railing posts are inserted into the tubular railing brackets. The actual railing consists of a chain, a rope, or a lattice. Furthermore, a folding ladder is attached to the maintenance floor. In the case of suspended maintenance cars, the ladder is located on top of the maintenance platform and folded upward for services to be performed on the rails and/or rail car on the rail. For maintenance cars running on rails rather than being suspended, the ladder is arranged below the maintenance floor and folds out below.
The maintenance car has a current accumulator consisting of a battery which provides the displacement motor, the extension motor and the drive motor of the maintenance car with electric current during power failure. In order to keep the current accumulator and thus the weight of the maintenance car as small as possible, a combustion motor is provided as well which can supply energy for a prolonged period of time. For a further understanding of the invention reference is made to the drawings and the following detailed description illustrating an embodiment of the invention in the form of a suspended maintenance car in an elevated monorail system, although it will be understood that the invention may be utilized with cars operable on the rail, and that the invention is useful in dual rail systems as well.